As is well known to those skilled in the art, it is desirable to convert heavy hydrocarbons, such as those having a boiling point above about 1000.degree. F., into lighter hydrocarbons which are characterized by higher economic value. It is desirable to treat hydrocarbon feedstocks, particularly petroleum residue, to achieve other goals including hydrodesulfurization (HDS), carbon residue reduction (CRR), and hydrodemetallation (HDM)--the latter particularly including removal of nickel compounds (HDNi) and vanadium compounds (HDV).
These processes typically employ hydrotreating catalysts with specified ranges of pores having relatively small diameters (i.e. micropores, herein defined as pores having diameters less than 250 .ANG.) and pores having relatively large diameters (i.e. macropores, herein defined as pores having diameters greater than 250 .ANG.).
One approach to developing improved catalysts for petroleum resid processing has involved enlarging the micropore diameters of essentially monomodal catalysts (having no significant macroporosities) to overcome diffusion limitations. Catalysts which are essentially monomodal with small micropore diameters and low macroporosities, designed for improved petroleum resid HDS include for example, those disclosed in U.S. Pat. Nos. 4,738,944; 4,652,545; 4,341,625; 4,309,278; 4,306,965; 4,297,242; 4,066,574; 4,051,021; 4,048,060 (first-stage catalyst); 3,770,617; and 3,692,698, discussed herein. Essentially monomodal catalysts with larger micropore diameters and low macroporosities designed for improved petroleum resid HDM are typified by those disclosed in U.S. Pat. Nos. 4,328,127; 4,082,695; 4,048,060 (second-stage catalyst); and 3,876,523, discussed herein.
U.S. Pat. No. 4,738,944 (Robinson et al.) discloses a catalyst composition useful in the hydrotreatment of hydrocarbon oils, the catalyst containing nickel and phosphorus and about 19-21.5% Mo (calculated as the oxide) on a porous refractory oxide, having a narrow pore size distribution wherein at least 10% of the Total Pore Volume is in pores having diameters less than 70 .ANG., at least 75% of the Total Pore Volume is in pores having diameters between 50-110 .ANG., at least 60% of the Total Pore Volume is in pores having diameters within about 20 .ANG. above and below the average pore diameter, and at most 25% of the Total Pore Volume, most preferably less than 10% of the Total Pore Volume is in pores having diameters greater than 110 .ANG.. The instant invention is distinguished from Robinson et al. (U.S. Pat. No. 4,738,944) in that Robinson et al. allows at most only 25% of the TPV in pores with diameters &gt;110 .ANG., whereas, the catalysts of the instant invention have about 50-60% of the TPV in pores with diameters greater than &gt;110 521 .
U.S. Pat. No. 4,652,545 (Lindsley et al.) discloses a catalyst composition useful in the hydroconversion of heavy oils, the catalyst containing 0.5-5% Ni or Co and 1.8-18% Mo (calculated as the oxides) on a porous alumina support, having 15-30% of the Ni or Co in an acid extractable form, and further characterized by having a Total Pore Volume (TPV) of 0.5-1.5 cc/g with a pore diameter distribution such that (i) at least 70% TPV is in pores having 80-120 .ANG. diameters, (ii) less than 0.03 cc/g of TPV is in pores having diameters of less than 80 .ANG., and (iii) 0.05-0.1 cc/g of TPV is in pores having diameters of greater than 120 .ANG..
U.S. Pat. No. 4,341,625 (Tamm) discloses a process for hydrodesulfurizing a metal-containing hydrocarbon feedstock which comprises contacting the feedstock with a catalyst comprising at least one hydrogenation agent (i.e. Group VIB or Group VIII metal, or combinations thereof) on a porous support, the catalyst being further characterized by having a TPV of 0.5-1.1 cc/g with at least 70% TPV in pores having diameters of 80-150 .ANG. and less than 3% TPV in pores having diameters greater than 1000 .ANG.. The instant invention is distinguished from Tamm (U.S. Pat. No. 4,341,625) in that Tamm allows at most only 3% of the TPV in pores with diameters &gt;1000 .ANG., whereas, the catalysts of the instant invention have about 15-20% of the TPV in pores with diameters greater than &gt;1000 .ANG..
U.S. Pat. No. 4,309,278 (Sawyer) discloses a process for the hydroconversion of a hydrocarbon feedstock comprising contacting the feedstock with hydrogen and a catalyst in a fixed bed, moving bed, ebullated bed, slurry, disperse phase, or fluidized bed reactor, where the catalyst comprises a hydrogenation component (i.e. Group VIB or Group VIII metal) on a porous support, and is further characterized by having a BET Surface Area of 250-450 m.sup.2 /g, a BET Pore Volume of 0.9-2.0 cc/g with no more than 0.05-0.20 cc/g of TPV in pores having diameters of greater than 400 .ANG..
U.S. Pat. No. 4,306,965 (Hensley, Jr. et al.) discloses a process for the hydrotreatment of a hydrocarbon stream comprising contacting the stream with hydrogen and a catalyst, the catalyst comprising chromium, molybdenum, and at least one Group VIII metal on a porous support, further characterized by having a TPV of 0.4-0.8 cc/g with 0-50% TPV in pores having diameters smaller than 50 .ANG., 30-80% TPV in pores having diameters of 50-100 .ANG., 0-50% TPV in pores having diameters of 100-150 .ANG., and 0-20% TPV in pores having diameters greater than 150 .ANG.. The instant invention is distinguished from Hensley, Jr. et al. (U.S. Pat. No. 4,306,965) in that Hensley, Jr. et al. allows at most only 20% of the TPV in pores with diameters &gt;150 .ANG., whereas, the catalysts of the instant invention have about 35-40% of the TPV in pores with diameters greater than &gt;150 .ANG..
U.S. Pat. No. 4,297,242 (Hensley, Jr. et al.) discloses a two-stage process for the catalytic hydrotreatment of hydrocarbon streams containing metal and sulfur compounds, the process comprises: (i) first contacting the feedstock with hydrogen and a demetallation catalyst comprising a Group VIB and/or Group VIII metal; and (ii) thereafter reacting the effluent with a catalyst consisting essentially of at least one Group VIB metal on a porous support, and having a TPV of 0.4-0.9 cc/g and a pore size distribution such that pores having diameters of 50-80 .ANG. constitute less than 40% TPV, pores having diameters of 80-100 .ANG. constitute 15-65% TPV, pores having diameters of 100-130 .ANG. constitute 10-50% TPV, and pores having diameters of greater than 130 .ANG. less than 15% TPV.
U.S. Pat. No. 4,066,574 (Tamm) discloses a catalyst composition useful in the hydrodesulfurization of a hydrocarbon feedstock containing organometallic compounds, the catalyst comprising Group VIB and Group VIII metal components on a porous support, and having a TPV of 0.5-1.1 cc/g with a pore diameter distribution such that at least 70% TPV is in pores of diameters of 80-150 .ANG. and less than 3% TPV is in pores having diameters greater than 1000 .ANG..
U.S. Pat. No. 4,051,021 (Hamner) discloses a catalytic process for the hydrodesulfurization of a hydrocarbon feed which comprises contacting the feed with hydrogen and a catalyst, the catalyst comprising a Group VIB and Group VIII metal on a porous support, having a TPV of 0.3-1.0 cc/g with a pore diameter distribution such that greater than 50% TPV is in pores of diameters of 70-160 .ANG., and pores having diameters below 70 .ANG. and above 160 .ANG. are minimized.
U.S. Pat. No. 4,048,060 (Riley) discloses a two-stage process for hydrodesulfurizing a heavy hydrocarbon feed which comprises: (i) contacting the feed with hydrogen and a first catalyst to produce a first hydrodesulfurized hydrocarbon product, the first catalyst comprising a Group VIB and Group VIII metal on a porous support and having a mean pore diameter of 30-60 .ANG.; and (ii) contacting the first hydrodesulfurized hydrocarbon product with hydrogen and a second catalyst under hydrodesulfurization conditions, the second catalyst comprising a Group VIB and Group VIII metal on a porous support, further characterized by having a TPV of 0.45-1.50 cc/g with 0-0.5 cc/g of TPV in pores having diameters greater than 200 .ANG., 0-0.05 cc/g of TPV in pores having diameters below 120 .ANG., and at least 75% TPV in pores having diameters .+-.10 .ANG. of a mean pore diameter of 140-190 .ANG..
U.S. Pat. No. 3,770,617 (Riley et al.) discloses a process for the desulfurization of a petroleum hydrocarbon feed comprising contacting the feed with hydrogen and a catalyst, the catalyst comprising a Group VIB or Group VIII metal on a porous support having greater than 50% TPV in pores of 30-80 .ANG., less than 4% TPV in pores having diameters 200-2000 .ANG., and at least 3% TPV in pores having diameters greater than 2000 .ANG.. The instant invention is distinguished from Riley et al. (U.S. Pat. No. 3,770,617) in that Riley et al. allows at most only 4% of the TPV in pores with diameters between 200-2000 .ANG., whereas, the catalysts of the instant invention have about 15-20% of the TPV in pores with diameters between 200-2000 .ANG..
U.S. Pat. No. 3,692,698 (Riley et al.) discloses a catalyst useful in hydroprocessing of heavy feed stocks, the catalyst comprising a mixture of Group VIB and Group VIII metals on a porous support having a pore size distribution such that a major portion of its TPV is in pores of diameters ranging from 30-80 .ANG., less than 4% TPV is in pores of diameters of 200-2000 .ANG., and at least 3% TPV is in pores of diameters greater than 2000 .ANG.. The instant invention is distinguished from Riley et al. (U.S. Pat. No. 3,692,698) in that Riley al. allows at most only 4% of the TPV in pores with diameters between 200-2,000 .ANG., whereas, the catalysts of the instant invention have about 15-20% of the TPV in pores with diameters between 200-2,000 .ANG..
U.S. Pat. No. 4,328,127 (Angevire et al.) discloses a catalyst composition for use in the hydroclemetallation-desulfurization of residual petroleum oils, the catalyst comprising a hydrogenating component (i.e. Group VIB or Group VIII metal, or combinations thereof) on a porous support, further characterized by having a TPV of 0.45-1.5 cc/g with 40-75% TPV in pores having diameters of 150-200 .ANG., and up to 5% TPV in pores having diameters of greater than 500 .ANG..
U.S. Pat. No. 4,082,695 (Rosinski et al.) discloses a catalyst for use in the demetallation and desulfurization of petroleum oils, the catalyst comprising a hydrogenating component (i.e. cobalt and molybdenum) on a porous support, and having a surface area of 110-150 m.sup.2 /g and a pore size distribution such that at least 60% of TPV is in pores having diameters of 100-200 .ANG. and not less than 5% TPV is in pores having diameters greater than 500 .ANG..
U.S. Pat. No. 3,876,523 (Rosinski et al.) discloses a process for the demetallizing and desulfurizing of residual petroleum oil comprising contacting the oil with hydrogen and a catalyst, the catalyst comprising a Group VIB and Group VIII metal on a porous support having a pore size distribution such that greater than 60% TPV is in pores having diameters of 100-200 .ANG., at least 5% TPV is in pores having diameters greater than 500 .ANG., 10% TPV or less is in pores having diameters less than 40 .ANG., and the surface area of the catalyst is 40-150 m.sup.2 /g.
Early petroleum distillate hydrotreating catalysts generally were monomodal catalysts with very small micropore diameters (less than say 100 .ANG.) and rather broad pore size distributions. First generation petroleum resid hydrotreating catalysts were developed by introducing a large amount of macroporosity into a distillate hydrotreating catalyst pore structure to overcome the diffusion resistance of large molecules. Such catalysts, which are considered fully bimodal HDS/HDM catalysts, are typified by U.S. Pat. Nos. 5,221,656, 4,746,419, 4,395,328, 4,395,329, and 4,089,774, discussed herein.
U.S. Pat. No. 5,221,656, to Clark et al. discloses a hydroprocessing catalyst comprising at least one hydrogenation metal selected from the group consisting of the Group VIB metals and Group VIII metals deposited on an inorganic oxide support, said catalyst characterized by a surface area of greater than about 220 m.sup.2 /g, a pore volume of 0.23-0.31 cc/g in pores with radii greater than about 600 .ANG. (i.e., in pores with diameters greater than 1200 .ANG.), an average pore radius of about 30-70 .ANG. in pores with radii less than about 600 .ANG. (i.e., an average pore diameter of about 60-140 .ANG. in pores with diameters less than about 1200 .ANG.), and an incremental pore volume curve with a maximum at about 20-50 .ANG. radius (i.e., at about 40-100 .ANG. diameter). In the instant invention, pores having a diameter greater than 1200 .ANG. are only about 0.15-0.20 cc/g.
U.S. Pat. No. 4,746,419 (Peck et al.) discloses an improved hydroconversion process for the hydroconversion of heavy hydrocarbon feedstocks containing asphaltenes, metals, and sulfur compounds, which process minimizes the production of carbonaceous insoluble solids and catalyst attrition rates. Peck et al. employs a catalyst which has 0.1 to 0.3 cc/g of its pore volume in pores with diameters greater than 1,200 .ANG. and no more than 0.1 cc/g of its pore volume in pores having diameters greater than 4,000 .ANG.. The instant invention will be distinguished from Peck, et al. (U.S. Pat. No. 4,746,419) in that Peck discloses only features of macropore size distribution useful for minimizing the production of carbonaceous insoluble solids and does not disclose a pore size distribution which would provide additional catalytic activities, whereas, the catalysts of the instant invention require a unique pore size distribution in order to provide additional catalytic activities (e.g., hydrodesulfurization). The instant invention gives improved levels of hydrodesulfurization, particularly improved sulfur removal from the unconverted 1000.degree. F.+ boiling point products, improved levels of carbon residue reduction, and nickel and vanadium removal and reduced sediment make at the same operating conditions and allows operations at higher temperatures compared to operations with a commercial vacuum resid hydroconversion catalyst having a macropore size distribution which satisfies the requirements of Peck, et al. (U.S. Pat. No. 4,746,419).
U.S. Pat. No. 4,395,328 (Hensley, Jr. et al.) discloses process for the hydroconversion of a hydrocarbon stream containing asphaltenes and a substantial amount of metals, comprising contacting the stream (in the presence of hydrogen) with a catalyst present in one or more fixed or ebullating beds, the catalyst comprising at least one metal which may be a Group VIB or Group VIII metal, an oxide of phosphorus, and an alumina support, where the alumina support material initially had at least 0.8 cc/g of TPV in pores having diameters of 0-1200 .ANG., at least 0.1 cc/g of TPV is in pores having diameters of 1200-50,000 .ANG., a surface area in the range of 140-190 m.sup.2 /g, and the support material was formed as a composite comprising alumina and one or more oxides of phosphorus into a shaped material and was thence heated with steam to increase the average pore diameter of the catalyst support material prior to impregnation with active metals. The instant invention is distinguished from Hensley, Jr., et al. in that the support of the instant invention does not contain one or more oxides of phosphorus, is not heated with steam to increase the average pore diameter, and requires a higher surface area of about 250-330 m.sup.2 /g and there is a much more precise definition of pore volume distribution.
U.S. Pat. No. 4,395,329 (Le Page et al.) discloses a hydrorefining process of a high metal-containing feedstock employing a catalyst containing alumina, a metal from group VI and a metal from the iron group, the catalyst having a Total Surface Area of 120-200 m.sup.2 /g, a Total Pore Volume of 0.8-1.2 cc/g, and a Pore Diameter Distribution whereby 0-10% of the Total Pore Volume is present as micropores with diameters less than 100 .ANG., 35-60% of the Total Pore Volume is in pores with diameters of 100-600 .ANG., and 35-55% of the Total Pore Volume is present as macropores of diameter greater than 600 .ANG.. The instant invention is distinguished from Le Page et al. (U.S. Pat. No. 4,395,329) in that Le Page et al. requires 35-55% of the TPV in pores with a diameter &gt;600 .ANG. and the catalysts of the instant invention have only about 21-27% of the TPV in pores greater than 600 .ANG..
U.S. Pat. No. 4,089,774 (Oleck et al.) discloses a process for the demetallation and desulfurization of a hydrocarbon oil comprising contacting the oil with hydrogen and a catalyst, the catalyst comprising a Group VIB metal and an iron group metal (i.e. iron, cobalt, or nickel) on a porous support, and having a surface area of 125-210 m /g and TPV of 0.4-0.65 cc/g with at least 10% TPV in pores having diameters less than 30 .ANG., at least 50% of pore volume accessible to mercury being in pores having diameters of 30-150 .ANG., and at least 16.6% of pores accessible to mercury being in pores having diameters greater than 300 .ANG.. The instant invention is distinguished from Oleck et al. (U.S. Pat. No. 4,089,774) in that Oleck et al. requires a relatively low Total Pore Volume of only 0.4-0.65 cc/g, whereas, the catalysts of the instant invention require much higher Total Pore Volumes of 0.82-0.98 cc/g.
A recent approach to developing improved catalysts for the hydroconversion of feedstock components having a boiling point greater than 1000.degree. F. to products having a boiling point less than 1000.degree. F. has involved the use of catalysts having micropores intermediate between the above described monomodal HDS and HDM catalysts with pore volumes in the HDS type of range and with macroporosities sufficient to overcome the diffusion limitations for conversion of feedstock components having boiling points greater than 1000.degree. F. into products having boiling points less than 1000.degree. F. but limited macroporosities so as to limit poisoning of the interiors of the catalyst particles. Such catalysts are described in U.S. Pat. No. 5,397,456 (To Texaco as assignee of Dai et al.) and copending U.S. application Ser. No. 08/564,769, now U.S. Pat. No. 5,616,530 which is a divisional of U.S. application Ser. No. 08/130,472, now U.S. Pat. No. 5,514,273 discussed herein.
U.S. Pat. No. 5,397,456 (to Texaco as assignee of Dai et al.) discloses a catalyst composition useful in the hydroconversion of a sulfur- and metal-containing feedstock comprising an oxide of a Group VIII metal and an oxide of a Group V-IB metal and optionally phosphorus on a porous alumina support, the catalyst having a Total Surface Area of 240-310 m.sup.2 /g, a Total Pore Volume of 0.5-0.75 cc/g, and a Pore Diameter Distribution whereby 63-78% of the Total Pore Volume is present as micropores of diameter 55-115 .ANG. and 11-18% of the Total Pore Volume is present as macropores of diameter greater than 250 .ANG.. The heavy feedstocks are contacted with hydrogen and with the catalyst. The catalyst is maintained at isothermal conditions and is exposed to a uniform quality of feed. The process of Dai et al. is particularly effective in achieving desired levels of hydroconversion of feedstock components having a boiling point greater than 1000.degree. F. to products having a boiling point less than 1000.degree. F. The instant invention is distinguished from U.S. Pat. No. 5,397,456 in that Dai et al. requires a catalyst with a Pore Diameter Distribution wherein 63-78% of the Total Pore Volume is present as micropores of diameter 55-115 .ANG. and 11-18% of the Total Pore Volume is present as macropores of diameter greater than 250 .ANG., whereas, the catalysts employed in the instant invention have only about 45-55% of the Total Pore Volume present as micropores of diameter 55-115 .ANG. and 22.0-33.0% of the Total Pore Volume is present as macropores of diameter greater than 250 .ANG..
In related copending U.S. application Ser. No. 08/564,769, now U.S. Pat. No. 5,616,530 which is a divisional of U.S. application Ser. No. 08/130,472, now U.S. Pat. No. 5,514,273 there is disclosed a hydrotreating process and catalyst wherein the Median Pore Diameter by Surface Area is in the range of 70-90 .ANG., 50-62.8% of the TPV is present in micropores of diameter 55-115 .ANG. and 20-30.5% of the TPV is present as macropores of diameter greater than 250 .ANG.. In the instant case, the catalyst is required to have a Median Pore Diameter by Surface Area of 91-104 .ANG., preferably 91-99 .ANG..
Another recent approach to developing improved catalysts for petroleum resid processing has involved the use of catalysts having micropore diameters intermediate between the above described monomodal HDS and HDM catalysts, as well as sufficient macroporosities so as to overcome the diffusion limitations for petroleum bottoms HDS (i. e., sulfur removal from hydrocarbon product of a hydrotreated petroleum resid having a boiling point greater than 1000.degree. F.) but limited macroporosities to limit poisoning of the interiors of the catalyst particles. Catalysts with micropore diameters intermediate between the above described monomodal HDS and HDM catalysts with limited macroporosities include those of U.S. Pat. Nos. 4,941,964, 5,047,142, 5,399,259 and copending U.S. application Ser. No. 08/425,971 now U.S. Pat. No. 5,545,662, which is a divisional of U.S. Pat. No. 5,435,908, and copending U.S. application Ser. Nos. 08/518,773 (D#92,121) and 08/518,774 (D#92,122), discussed herein.
U.S. Pat. No. 4,941,964 (to Texaco as assignee of Dai, et al.) discloses a process for the hydrotreatment of a sulfur- and metal-containing feed which comprises contacting said feed with hydrogen and a catalyst in a manner such that the catalyst is maintained at isothermal conditions and is exposed to a uniform quality of feed, the catalyst comprising an oxide of a Group VIII metal, an oxide of a Group VIB metal and 0-2.0 weight % of an oxide of phosphorus on a porous alumina support, having a surface area of 150-210 m.sup.2 /g and a Total Pore Volume (TPV) of 0.50-0.75 cc/g such that 70-85% TPV is in pores having diameters of 100-160 .ANG. and 5.5-22.0% TPV is in pores having diameters of greater than 250 .ANG..
U.S. Pat. No. 5,047,142 (to Texaco as assignee of Sherwood, Jr., et al.), discloses a catalyst composition useful in the hydroprocessing of a sulfur and metal-containing feedstock comprising an oxide of nickel or cobalt and an oxide of molybdenum on a porous alumina support in such a manner that the molybdenum gradient of the catalyst has a value of less than 6.0 and 15-30% of the nickel or cobalt is in an acid extractable form, having a surface area of 150-210 m.sup.2 /g, a Total Pore Volume (TPV) of 0.50-0.75 cc/g, and a pore size distribution such that less than 25% TPV is in pores having diameters less than 100 .ANG., 70.0-85.0% TPV is in pores having diameters of 100-160 .ANG. and 1.0-15.0% TPV is in pores having diameters greater than 250 .ANG..
U.S. Pat. No. 5,399,259 (to Texaco as assignee of Dai, et al.) discloses a process for the hydrotreatment of a sulfur-, metals- and asphaltenes-containing feed which comprises contacting said feed with hydrogen and a catalyst in a manner such that the catalyst is maintained at isothermal conditions and is exposed to a uniform quality of feed, the catalyst comprising 3-6 wt % of an oxide of a Group VIII metal, 14.5-24 wt % of an oxide of a Group VIB metal and 0-6 wt % of an oxide of phosphorus on a porous alumina support, having a surface area of 165-230 m.sup.2 /g and a Total Pore Volume (TPV) of 0.5-0.8 cc/g such that less than 5% of TPV is in pores with diameters less than about 80 .ANG., at least 65% of the pore volume in pores with diameters less than 250 .ANG. is in pores with diameters +/-20 .ANG. of a Pore Mode by Volume from mercury porosimetry of about 100-135 .ANG. and 22-29% TPV is in pores having diameters of greater than 250 .ANG.. The instant invention is distinguished from Dai et al. (U.S. Pat. No. 5,399,259) in that Dai et al. requires a relatively large Pore Mode by Volume from mercury porosimetry of 100-135 .ANG., whereas, the catalysts of the instant invention require a relatively small Pore Mode of only 86-99 .ANG.. In addition, Dai et al. requires a relatively low Total Pore Volume of only 0.5-0.8 cc/g, whereas, the catalysts of the instant invention require much higher Total Pore Volumes of 0.82-0.98 cc/g.
In copending U.S. application Ser. No. 08/425,971 now U.S. Pat. No. 5,545,602 which is a divisional of U.S. Pat. No. 5,435,908 (to Texaco as assignee of Nelson et al.) there is disclosed a hydrotreating process employing, as catalyst, a porous alumina support with pellet diameters of 0.032-0.038 inches bearing 2.5-6 wt % of a Group VIII non-noble metal oxide, 13-24 wt % of a Group VIB metal oxide, less than or equal to 2.5 wt % of silicon oxide, typically about 1.9-2 wt % of intentionally added silica oxide, and 0-2 wt % of a phosphorus oxide, preferably less than about 0.2 wt % of a phosphorus oxide, with no phosphorus-containing components intentionally added during the catalyst preparation, said catalyst having a Total Surface Area of 165-210 m.sup.2 /g, a Total Pore Volume of 0.75-0.95 cc/g, and a Pore Diameter Distribution whereby 14-22% of the Total Pore Volume is present as macropores of diameter .gtoreq.1000 .ANG., 22-32% of the Total Pore Volume is present as pores of diameter .gtoreq.250 .ANG., 68-78% of the Total Pore Volume is present as pores of diameter &lt;250 .ANG., 26-35% of the Total Pore Volume is present as mesopores of diameters .gtoreq.200 .ANG., 34-69% of the Total Pore Volume is present as secondary micropores of diameters 100-200 .ANG., 5-18% of the Total Pore Volume is present as primary micropores of diameter .ltoreq.100 .ANG., and .gtoreq.57% of the micropore volume is present as micropores of diameter +/-20 .ANG. about a Pore Mode by Volume from mercury porosimetry of 100-145 .ANG.. The instant invention is distinguished from Nelson et al. (U.S. application Ser. No. 08/425,971 now U.S. Pat. No. 5,545,602) in that Nelson et al. requires a relatively large Pore Mode by Volume of 100-145 .ANG., whereas, the catalysts of the instant invention require a relatively small Pore Mode by Volume of only 86-99 .ANG.. In addition, Nelson et al. requires a relatively low Surface Area of only 165-210 m.sup.2 /g, whereas, the catalysts of the instant invention require much higher Surface Areas of 215-245 m.sup.2 /g.
In copending U.S. application Ser. No. 08/518,773 (D#92,121--to Texaco as assignee of Sherwood, Jr.) there is disclosed a hydrotreating process employing, as catalyst, a porous alumina support, containing less than or equal to 2.5 wt % of silicon oxide (e.g., silica: SiO.sub.2), bearing 2.2-6 wt % of a Group VIII non-noble metal oxide, 7-24 wt % of a Group VIB metal oxide, and 0.3-2 wt % of a phosphorus oxide, preferably 0.5-1.5 wt % of P.sub.2 O.sub.5, said catalyst having a Total Surface Area of 175-205 m.sup.2 /g, a Total Pore Volume of 0.82-0.98 cc/g, and a Pore Diameter Distribution whereby 29.6-33.0% of the Total Pore Volume is present as pores of diameter .gtoreq.25 .ANG., 67.0-70.4%, of the Total Pore Volume is present as pores of diameter .ltoreq.250 .ANG., .gtoreq.65% of the micropore volume is present as micropores of diameters +/-25 .ANG. about a Pore Mode by Volume from mercury porosimetry of 110-130 .ANG., and less than 0.05 cc/g of micropore volume is present in micropores with diameters less than 80 .ANG.. The instant invention is distinguished from Sherwood, Jr. (U.S. application Ser. No. 08/518,773--D#92,121) in that Sherwood, Jr. requires a relatively large Pore Mode of 110-130 .ANG., whereas, the catalysts of the instant invention require a relatively small Pore Mode of only 86-99 .ANG.. In addition, Sherwood, Jr. requires a relatively low Surface Area of only 175-205 m.sup.2 /g, whereas, the catalysts of the instant invention require much higher Surface Areas of 215-245 m.sup.2 /g.
In copending U.S. application Ser. No. 08/518,774 (D#92,122--to Texaco as assignee of Sherwood, Jr.) there is disclosed a hydrotreating process employing, as catalyst, a nominally pure, porous alumina support, containing less than or equal to 0.5 wt % of silica, with no silicon containing components intentionally added during catalyst preparation, bearing 2.2-6 wt % of a Group VIII non-noble metal oxide, 7-24 wt % of a Group VIB metal oxide, and 0-2 wt % of a phosphorus oxide, preferably less than 0.2 wt % of a phosphorus oxide, most preferably less than 0.1 wt % of a phosphorus oxide, with no phosphorus containing components intentionally added during the catalyst preparation, said catalyst having a Total Surface Area of 195-230 m.sup.2 /g, a Total Pore Volume of 0.82-0.98 cc/g, and a Pore Diameter Distribution whereby 27.0-34.0% of the Total Pore Volume is present as pores of diameter .gtoreq.250 .ANG., 66.0-73.0% of the Total Pore Volume is present as pores of diameter .ltoreq.250 .ANG., 55-64.5% of the micropore volume is present as micropores of diameters +/-25 .ANG. about a Pore Mode by Volume from mercury porosimetry of 110-130 .ANG., and less than 0.05 cc/g of micropore volume is present in micropores with diameters less than 80 .ANG.. The instant invention is distinguished from Sherwood, Jr. (U.S. application Serial No. 08/518,774--D#92,122) in that Sherwood, Jr. requires a relatively large Pore Mode of 110-130 .ANG., whereas, the catalysts of the instant invention require a relatively small Pore Mode of only 86-99 .ANG..
None of the above-identified catalyst types in the art have been found to be effective for achieving all of the desired improved process needs. Early catalysts in the art addressed the need for improved hydrodesulfurization and/or hydrodemetallation as measured in the total liquid product.
One recent line of catalyst development, as typified by U.S. Pat. No. 5,397,456 and copending U.S. application Ser. No. 08/564,769, now U.S. Pat. No. 5,616,530, which is a divisional of U.S. application Ser. No. 08/130,472, now U.S. Pat. No. 5,514,273 has been to develop hydroconversion catalysts for the improved hydroconversion of feedstocks components having a boiling point greater than 1000.degree. F. to products having a boiling point less than 1000.degree. F. The most recent developments of hydroconversion catalysts, as typified by copending U.S. application Ser. No. 08/564,769, now U.S. Pat. No. 5,616,530 which is a divisional of U.S. application Ser. No. 08/130,472, now U.S. Pat. No. 5,514,273 have been to develop hydroconversion catalysts having Median Pore Diameters by Surface Area from mercury porosimetry of 70-90 .ANG., preferably 75-85 .ANG., with slightly improved bottoms HDS activities (i. e., selective sulfur removal from the unconverted hydrocarbon product having a boiling point greater than 1000.degree. F. from a hydroprocess operating with significant hydroconversion of feedstocks components e.g., petroleum resids! having a boiling point greater than 1000.degree. F. to products having a boiling point Less than 1000.degree. F.) and some slight degree of sediment control allowing the use of some higher temperatures and reducing sediment make. Although the above-described hydroconversion catalysts give improved levels of hydroconversion of feedstocks components having a boiling point greater than 1000.degree. F. to products having a boiling point less than 1000.degree. F., they do not give the desired levels of sulfur removal obtained from the below-described petroleum bottoms HDS catalysts and these hydroconversion catalysts still make some amount of sediment.
A second line of catalyst development, as typified by U.S. Pat. Nos. 4,941,964 and 5,047,142, has been to develop improved catalysts for petroleum bottoms HDS. These catalysts contain the majority of micropore volume (70-85% of the Total Pore Volume) in pores with diameters between 100 .ANG. and 160 .ANG.. More recent developments of petroleum bottoms HDS catalysts, as typified by U.S. Pat. No. 5,399,259 and copending U.S. application Ser. No. 08/425,971 now U.S. Pat. No. 5,545,602, which is a divisional of U.S. Pat. No. 5,435,908, and copending U.S. application Ser. Nos. 08/518,773 (D#92,121) and 08/518,774 (D#92,122) have been to develop petroleum bottoms HDS catalysts having Pore Modes by Volume as determined by mercury porosimetry of 100-145 .ANG., particularly, 110-130 .ANG., which also give a degree of sediment control allowing the use of higher temperatures and reducing sediment make. The catalysts of U.S. application Ser. No. 08/518,773 (D#92,121) also give somewhat improved levels of hydroconversion of feedstocks components having a boiling point greater than 1000.degree. F. to products having a boiling point less than 1000.degree. F. while, at the same time, reducing sediment make. However, the catalysts of U.S. application Ser. No. 08/518,773 (D#92,121) give only moderate improvements in hydrodesulfurization activity (i.e., only +1.4% HDS when run at the same conditions as a commercial resid treating catalyst and only +4.2% HDS when the temperature is raised 10.degree. F.).
It would be desirable if a catalyst were available which provided hydroconversion, improved HDS, particularly improved bottoms HDS, and no sediment make and which could also withstand operation at higher temperatures, so that it would be possible to attain an even higher level of hydroconversion without the undesirable formation of sediment. It would also be desirable if such a catalyst could also give improved levels of sulfur removal from the converted 650-1000.degree. F. product stream and even higher levels sulfur removal from the unconverted hydrocarbon product having a boiling point greater than 1000.degree. F. Undesirable low levels of hydroconversion represent a problem which is particularly acute for those refiners who operate vacuum resid hydroprocessing units near their sediment limit. Such refiners, in the absence of sediment, would raise temperature and thus hydroconversion level. Undesirably high levels of sulfur in the converted 650-1000.degree. F. product stream can cause problems in further down-stream processing (e.g., excessive sulfur oxide emissions when used as a feed for Fluid Catalyst Cracking Units--FCCU's). Undesirably high levels of sulfur in the unconverted hydrocarbon product having a boiling point greater than 1000.degree. F. severely lowers its economic value (e.g., when used as a blending component for fuel oil).
The catalysts of the instant invention have micropore diameters intermediate between those of the above described hydroconversion catalysts and those of the abovedescribed petroleum bottoms HDS catalysts. The catalysts of the instant invention have relatively larger Median Pore Diameters from mercury porosimetry when compared to the abovedescribed hydroconversion catalysts. The catalysts of the instant invention have relatively smaller Pore Modes by Volume from mercury porosimetry when compared to the abovedescribed petroleum bottoms HDS catalysts. The catalysts of the instant invention also have sufficient macroporosities to overcome diffusion limitations imposed by the relatively large size of reactant feed molecules but limited macroporosities so as to limit poisoning of the interiors of the catalyst pellets.
It is an object of this invention to provide a process for hydroconverting a charge hydrocarbon feed, particularly, to hydroconvert feedstock components having boiling points greater than 1000.degree. F. into products having boiling points less than 1000.degree. F. while simultaneously removing high amounts of sulfur, particularly from the unconverted 1000.degree. F.+ product stream. It is also an object of this invention to provide conversion at low Existent IP Sediment values in the 650.degree. F.+ boiling point product (Discussed below under "Sediment Measurement"). It is also an object of this invention to allow the use of higher operating temperatures with reduced sediment make. It is also an object of this invention to give improved relative levels of sulfur removal from the converted 650-1000.degree. F. product stream and even higher relative levels of sulfur removal from the unconverted hydrocarbon product having a boiling point greater than 1000.degree. F. at these higher operating temperatures. Other objects will be apparent to those skilled in the art.